Abstract
We report on calculated outer-shell photodetachment cross sections from the metastable states in and negative ions in the photon energy range . Double-ionization thresholds for and as well as doubly excited thresholds of the residual atoms and are located within the photon energy range considered and thus doubly and triply excited states of both and are reached. We use a complex scaled configuration interaction (CSCI) method for the three active electrons supplemented with a sophisticated model potential as developed by Laughlin [Phys. Scr. 45, 238 (1992)] to account for core-valence interactions. The CI calculations are based on and one-electron orbitals expanded in terms of -spline basis set. We compare our cross sections with the only calculation available up to a photon energy [Zeng et al., Phys. Rev. A 62, 022713 (2000)] performed by using the -matrix method, in which only one resonance for and two ( and ) for were predicted. In this work, by analyzing both the cross sections and the locations of the -matrix poles in the complex plane, we are able to predict six , four , and four resonant states for , and three and two resonant states in .
- Received 20 June 2008
DOI:https://doi.org/10.1103/PhysRevA.78.053411
©2008 American Physical Society